A Ukrainian man sitting in seat 2F said he had a bomb and demanded the flight be diverted to Russia.

Safe landing ... the man (right) who attempted to hijack the airliner from Ukraine is spoken to by flight attendants after th...Source:AFP

When the man tried unsuccessfully to get in the cockpit, the pilot emitted a hijack alert and the Turkish F-16 military jet was scrambled.

The plane was immediately stormed by Turkish anti-terrorism commandos after it landed and the man seized, reports said.

Turkish officials are yet to confirm whether explosives were found on board.

Turkish television channels showed images of the aircraft surrounded by ambulances, fire engines and police vehicles with flashing lights.

Media pack ... the Governor of Istanbul Huseyin Avni Mutlu (centre) speaks to the press gathered at the airport in Istanbul.Source:AFP

They showed a still image of the would-be hijacker, in his 30s or 40s, with short hair and wearing what looked like a red, white, and blue ice hockey shirt with the number 11.

Flight crew told him "Yes, we are directing the flight to Sochi," but then turned off the in-flight monitors and instead continued to Turkey, a transportation official told NBC News.

The pilot sounded the hijacking alert, and two F-16 Turkish military jets were scrambled and escorted the plane to land at Sabiha Gokcen Airport in Istanbul.

Attempted hijacking...The crew told the man that the flight was being diverted to Sochi, then switched off in-flight monitors...Source:Supplied

The man told the crew a bomb was in the baggage hold, Transportation Ministry official Habip Soulk told CNN.

"While the plane was in the air, one of the passengers said that there was a bomb on board and asked the plane to not land in Sabiha Gokcen (in Turkey) but rather to land in Sochi," Mr Soluk told CNNTurk.

The man was intoxicated, reports Interfax, a Russian news agency.

The head of Turkey's main pilots' union, Gurcan Manti, told the NTV television channel: "I received confirmation that everyone on board is okay and that the plane is fine. I know the pilot ... he is experienced and I am sure everything is fine."

The plane from Kharkov, Ukraine, to Istanbul is now parked in a "safe area" at Istanbul's Sabiha Gokcen airport where it is being searched.

The in-flight incident occurred as the Winter Olympic Games kicked off the Opening Ceremony, amid intense security and fears of a potential terror attack.

Forty heads of state and leaders including UN Secretary General Ban Ki-moon and Chinese President Xi Jinping attended the Opening Ceremony.

Russia has vowed "the safest Olympics in history", with 100,000 police, army troops and security forces flooding Sochi.

However a string of recent suicide bombings have left athletes, spectators and officials on edge.

Security experts warn that Islamic militants in the Caucasus, who have threatened to derail the Winter Games that run from February 7-23, could achieve their goal by choosing soft targets away from the Olympic sites or even outside Sochi.

The back-to-back December suicide bombings of a railway station and a bus in Volgograd, about 640km east of Sochi, killed 34 people and demonstrated the militants' ability to strike with shocking ease.

A jihadist group in Dagestan, the epicentre of the Islamic rebellion against Russia that has engulfed the Caucasus, claimed responsibility for the Volgograd bombings and has threatened to strike Sochi.